Step-by-step control device



May 1.2, 1964 ROCTQN 3,132,527

STEP-BYSTEP CONTROL DEVICE Filed Feb. 23, 1961 Amen/Eh United States Patent Office 3,132,527 Patented May 12, 1964 3,132,527 STEP-EYSTEP CONTR DL DEVICE Lucien Roc'ton, Malakofi, France, assignor to Compagnie Indnstrielle des Telephones, Paris, France Filed Feb. 23, 1961, Ser. No. 91,143 Claims priority, application France Mar. 5, 1960 17 Claims. (Cl. 74-84) The present invention relates to a step-by-step control device, and more particularly to a step-by-step control arrangement applicable, in particular, to the entrainment of a rotating commutator.

The rotating commutators are generally driven by a control device provided with a ratchet wheel when it is desired to obtain a duration of passage from one position to the next which is very short with respect to the duration of stoppage in each position.

Such prior art ratchet-type driving devices, however, present significant and important inconveniences, in particular when the commutator is utilized for cyclic measures. In fact, in the latter case, any irregularity in the passage from one position to the next causes a displacement of the measures which completely mutilates the interpretation thereof. Moreover, the very abrupt accelerations cause fatigue in the elements thereof and, in particular when the commutator has to assure a continuous permanent service, the wear of the pawl and of the teeth is rapid.

Furthermore, the ratchet wheel is normally driven by an electromagnet, energized by means of an electric contact which operates at a very high frequency, so that a rapid wear of the contacts results therefrom. On the other hand, the operation of such prior art devices depends on a large number of elements arranged in series, namely on the control of the electric contact determining the time base, the electric contact, the electromagnet, and the ratchet wheel. It follows therefrom that the demarkation and cut-off of the signals very often is neither rigorous nor stable within time.

The present invention enables the avoidance of these inconveniences encountered with these prior art devices while assuring at the same time a cutoff of the signals with a very high precision and a duration of the passage from one position to the other which is very short with respect to the duration of stoppage.

Accordingly, the present invention has for its object a device for the step-by-step control, applicable in particular to the entrainment of a rotating commutator, which avoids the inconveniences and shortcomings of the prior art construction.

It is another object of the present invention to provide a step-by-step control system that may be used with rotating conimutators, which assures high accuracy in the cyclic signals produced thereby and involves relatively little wear of its elements during operation thereof.

Another object of the present invention resides in the provision of a step-by-step control system, especially for rotating cornmutators, which eliminates the necessity of a large number of elements connected in seriatim, all of which have to operate properly as a prerequisite for proper operation of the control system.

A still further object of the present invention resides in the provision of a step-by-step control arrangement which provides an extremely accurate operation and permits the realization of relatively brief operating periods as compared to the relatively long rest periods of the system.

Still another object of the present invention resides in the provision of a step-by-step control arrangement which produces highly accurate, well defined and precisely cutolf signals.

These and other objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing, which shows in the several views thereof, for purposes of illustration only, one embodiment in accordance with the present invention, and wherein:

FIGURE 1 is a schematic perspective view of a control arrangement in accordance with the present invention, and

FIGURE 2 is a schematic end view of the disk 4 and of the wheel 6 of FIGURE 1, illustrating schematically the inter-engagement thereof.

The present invention essentially consists of a driving means such as a driving motor determining the time base, a first and second disk having a circular profile and mounted, for common rotation, on a shaft driven by the driving means, a first and a second toothed wheel mounted, for common rotation, on a driven shaft and located opposite the two disks, respectively, for operative engagement therewith, the first disk including at least one notch followed directly by a projecting tooth capable to mesh with the first toothed wheel, the second disk comprising the same number of projecting teeth as the first disk each displaced ahead to provide a leading phase displacement with respect to a corresponding tooth of the first disk in such a manner as to entrain a tooth of the first toothed disk in a notch of the first disk as soon as this notch arrives opposite the toothed wheel.

Referring now to the drawing, wherein like reference numerals are used throughout the two views to designate corresponding parts, and more particularly to FIG- URE 1, reference numeral 1 designates therein the driving means of any suitable construction such as a synchronous motor which determines the time base of the device. The synchronous motor 1 drives, by means of any suitable speed reduction gearing having an appropriate speed reduction, two disks 2 and 4 both of which are mounted on the same driving shaft 1' for common rotation therewith.

The right disk 2, i.e., the right disk as viewed in FIG- URE 1, includes a projecting tooth 3 mounted on the disk 2 by means of an elastic mounting 11 forming a suitable yieldable damping means, whereby the elastic mounting 11 may be constituted by synthetic rubber cushions as indicated, for illustrative purposes only, in the drawing or by any other suitable elastic mounting means, for example, by a mounting formed by appropriate springs or spring elements.

The disk 4 also comprises a projecting tooth 7 which is preceded immediately by a notch 17 in the normal direction of rotatidn of disk 4 indicated by the arrows in FIGURES l and 2.

Two toothed wheels 5 and 6 of suitable design and mounted for common rotation on a shaft 18, are mounted respectively opposite the disks 2 and 4 for engagement therewith. The two wheels 5 and 6 each include the same number of teeth and have a relative phase displacement corresponding to a one-half pitch. In the illustrated embodiment, the teeth provided on each wheel 5 and 6 number four, and the teeth of one wheel are displaced by 45 with respect to the teeth of the other. The disk 4 and the wheel 6 are arranged sufficiently close to one another and are of such contour, as illustrated in FIGURE 2, that the wheel 6 cannot rotate when the smooth portion of the disk 4, i.e., the circular portion thereof corresponding to the normal diameter thereof, faces the wheel 6, as illustrated in FIGURE 2, which in effect constitutes a blocking means for the shaft 18 on which the two wheels 5 and 6 are mounted by effectively playing the role of an abutment or stop means.

The toothed wheels 5 and 6 have preferably the same gear module, and th profile of the teeth thereof as well as those of the teeth of the disks 2 and 4 are normalized to this module.

In order to avoid shocks and vibrations at the end of each movement corresponding to a step-by-step engagement of the teeth of wheel 6 against disk 4, i.e., to avoid chattering, a brake of any suitable construction is provided which cooperates with the shaft 18 to effectively brake the same. In the illustrated embodiment of FIG- URE 1, the brake includes a drum 8 integral or rigidly connected with the shaft 18 and two brake shoes 9 and it) which brake, by frictional engagement, the drum 8 and therewith the shaft 18. However, it is understood that any other suitable brake arrangement may be used to brake the shaft 18 on which the Wheels and 6 are mounted,

The movement of the shaft 18 drives a shaft 12 of the commutator (not shown) by means of a suitable speed reduction, which in the illustrated embodiment is constituted by a worm gear drive and a suitable meshing gear set of spur gears, it being understood that any other speed reduction may be used which produces the proper desired speed reduction.

The position of the tooth 3 on the disk 2 with respect to the position of the tooth 7 on the disk 4 is displaced out of phase, ahead in the direction of rotation, by a value slightly greater than the pitch corresponding to the module of the wheels 5 and 6 and to the diameter of disk 2. It follows therefrom that when the tooth 3 of the disk 2 enters into contact with one of the teeth of wheel 5, the elastic mounting 11 of this tooth 3 undergoes a deformation by exercising a pressure on the wheel 5 which seeks to take along the wheel 6 mounted on shaft 18 for movement therewith. However, wheel 6 cannot rotate until it finds itself facing the notch 17, as illustrated in FIGURE 2. As soon as the notch 17 of the disk 4 appears in front of the wheel 6, a tooth of wheel 6 rapidly enters into the notch 17 and the tooth 7 of the disk 4 thereupon causes the wheel 6 to advance immediately thereafter, by a quarter of a turn in the illustrated embodiment. Immediately after the passage of the tooth 7', a smooth portion of the disk 4 faces the wheel 6 which immobilizes wheel 6, i.e., effectively prevents further rotation of the latter, as explained hereinabove.

In the embodiment illustrated herein, each of the disks 2 and 4 comprises only a single tooth 3 and 7, respectively; however, these disks 2 and 4 could also each include several identical teeth separated by a smooth disk surface having a circular profile. The teeth of a disk may be spaced from each other at equal distances or also at different distances depending on the operation of the commutator which is to be obtained therefrom.

The corresponding teeth of the two disks 2 and 4 are out of phase with respect to each other in the manner indicated hereinabove, and the teeth of the disk 4 are always precede-o also by a notch in the normal direction of rotation of the control installation.

It follows from the operation of the device disclosed herein that the duration of the passage from one position of the commutator to the next is exclusively a function of the linear speed of the teeth of the disks 2. and 4. The duration of stoppage in each position is exclusively also a function of this linear speed of the teeth and of the spacing along the pitch diameter. This duration, therefore, only depends on mechanical parameters which may be easily determined and are immovable in time. The cut-off of the signals emitted by the commutator, therefore, cannot vary except with the frequency of the current supplied to the synchronous motor 1 and will, therefore, remain perfectly stable. This operation takes place with relatively slight friction between moving pieces. Furthermore, the mechanism may be immersed within an oil bath containing a liquid having a high viscosity Whereby the mechanism will function with a degree of wear which is extremely slight. It is also noted that such wear would have to be quite substantial before it has any harmful effect on the functioning of the control device in accordance with the present invention.

While I have shown and described one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of many changes and modifications within the spirit and scope of the present invention, and I, therefore, do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

I claim:

1. A step by step control device, especially for driving rotating commutators, comprising driving means for establishing the time base of the device, first disk means and second disk means driven by said driving means, said first and second disk means being of essentially circular profile, driven shaft means including a first and a second toothed wheel each having the same number of teeth and mounted for common rotation therewith, one toothed wheel each being arranged facing a respective disk means, the teeth of one said wheels having a phase displacement with respect to the teeth of the other wheel substantially equal to one-half of the pitch of the teeth thereof, said first disk means being provided with notch means preceding immediately in the normal direction of rotation of said disk means a corresponding projecting tooth means adapted to engage with the teeth of said first wheel, said second disk means having projecting tooth means adapted to engage with the teeth of said second wheel and displaced ahead, in the normal direction of rotation of said disk means, with respect to the corresponding tooth means of said first disk means in such a manner that a tooth of said first wheel engages into the notch means of said first disk means as soon as said notch means arrives opposite said first toothed wheel.

2. A precision step by step control device, especially for driving rotating commutators to produce sharply defined and accurately spaced signals, comprising input means establishing the time base of the device, output means, two sets of intermittently-operable rotating means each including first and second means adapted to engage with one another, the first means of each set being operatively connected with said input means and the second means of each set being operatively connected with said output means, engaging means on the first and second means of said first set operative upon actuation of the first means thereof by said input means to seek entrainment of said output means, engaging means in the first and second means of said second set including blocking means for temporarily blocking the operative engagement of said last-mentioned enga ing means and therewith preventing rotation of said output means until a predetermined relatively short period of time after operative engagement of the first and second means of said first-mentioned engaging means, one of said set means including means enabling relative phase displacement of the engaging means thereof with respect to the corresponding engaging means of the other set during said period of time, and means in said engaging means to rotate said output means through only a predetermined angle after said blocking means becomes ineffective after said period of time.

3. A step by step control device, especially for driving rotating commutators, comprising driving means for establishing the time base of the device, first disk means and second disk means driven by said driving means, said first and second disk means being of essentially circular profile, driven shaft means including a first and a second toothed wheel each having the same number of teeth and mounted for common rotation therewith, one toothed wheel each being arranged facing a respective disk means, the teeth of one said wheels having a phase displacement with respect to the teeth of the other wheel substantially equal to one-half of the pitch of the wheels, said first disk means being provided with a plurality of notches each preceding immediately in the normal direction of rotation of said disk means a corresponding projecting tooth adapted to engage with the teeth of said first wheel, said notch and tooth combinations being separated by surfaces of essentially circular profile, said second disk means having a plurality of projecting teeth adapted to engage with the teeth of said second wheel and each displaced ahead, in the normal direction of rotation of said disk means, with respect to a corresponding tooth of said first disk means in such a manner that a tooth of said first wheel engages into the corresponding notch of said first disk means as soon as said notch arrives opposite said first toothed wheel.

4. A step by step control device, especially for driving rotating commutators, comprising driving means for establishing the time base of the device, first disk means and second disk means driven by said driving means, said first and second disk means being of essentially circular profile, driven shaft means including afirst and a second toothed wheel each having the same number of teeth and mounted for common rotation therewith, one toothed Wheel each being arranged facing a respective disk means, the teeth of one said wheels having a phase displacement with respect to the teeth of the other wheel substantially equal to one-half of the pitch of the wheels, said first disk means being provided with notch means followed directly in the normal direction of rotation of said disk means by a corresponding projecting tooth means adapted to engage with the teeth of said first wheel, said first disk means and said first toothed wheel being so spaced relative to each other that said first toothed wheel is unable to rotate when facing a portion of circular profile of said first disk means, said second disk means having projecting tooth means adapted to engage with the teeth of said second wheel and displaced ahead, in the normal direction of rotation of said disk means, with respect to the corresponding tooth means of said first disk means in such a manner that a tooth of said first wheel engages into the notch means of said first disk means as soon as said notch means arrives opposite said first toothed wheel.

5. A precision step by step control device, especially for driving rotating commutators to produce sharply defined and accurately spaced signals, comprising input means establishing the time base of the device, output means, two sets of intermittently-operable rotating means each including first and second means adapted to engage with one another, the first means of each set being operatively connected with said input means and the second means of each set being operatively connected with said output means, engaging means on the first and second means of said first set operative upon actuation of the first means thereof by said input means to seek entrainment of said output means, engaging means in the first and second means of said second set including blocking means for temporarily preventing rotation of said output means until a predetermined relatively short period of time after engagement of said first-mentioned engaging means, one of said set means including means enabling relative displacement of the engaging means thereof during said period of time, and means in said engaging means to rotate said output means through only a predetermined angle after said blocking means becomes ineffective after elapse of said period of time.

6. A step by step control device, especially for driving rotating commutators, comprising driving means for establishing the time base of the device, a first disk and a second disk driven by said driving means, said disks being of essentially circular profile, driven shaft means including a first and a second toothed wheel each having the same number of teeth and mounted for common rotation therewith, said toothed Wheels having the same module, one toothed wheel each being arranged facing a respective disk, the teeth of one of said wheels having a phase displacement with respect to the teeth of the other wheel substantially equal to one-half of the pitch of the wheels, said first disk being provided with notch means followed directly in the normal direction of rotation of said disk means by a corresponding projecting tooth means adapted to engage with the teeth of said first wheel, said second disk having projecting tooth means adapted to engage with the teeth of said second Wheel and displaced ahead, in the normal direction of rotation of said disks, with respect to the corresponding tooth means of said first disk by a value slightly larger than the pitch corresponding to the module of said toothed Wheels and to the diameter of said second disk in such a manner that a tooth of said first wheel engages into the notch means of said first disk as soon as said notch means arrives opposite said first toothed wheel.

7. A step by step control device, especially for driving rotating commutators, comprising driving means for establishing the time base of the device, a first disk and a second disk driven by said driving means, said disks being of essentially circular profile, driven shaft means including a first and a second toothed wheel each having the same number of teeth and mounted for common rotation therewith, said toothed Wheels having the same module, one toothed wheel each being arranged facing a respective disk, the teeth of one of said wheels having a phase displacement with respect to the teeth of the other Wheel substantially equal to one-half of the pitch of the wheels, said first disk being provided with notch means followed directly in the normal direction of rotation thereof by a corresponding projecting tooth means adapted to engage With the teeth of said first wheel, said second disk having projecting tooth means adapted to engage with the teeth of said second wheel and displaced ahead, in the normal direction of rotation of said disks, with respect to the corresponding tooth means of said first disk by a value slightly larger than the pitch corresponding to the module of said toothed wheels and to the diameter of said second disk in such a manner as to insure that a tooth of said first wheel engages into the notch means of said first disk as soon as said notch means arrives opposite said first toothed wheel, and means for yieldingly mounting the tooth means of said second disk on the latter, and brake means effectively braking said output means to prevent shocks, at the end of each stepby-step movement, by the teeth of said first wheel against said first disk.

8. A precision step by step control device, especially for driving rotating commutators to produce sharply defined and accurately spaced signals, comprising continuously rotating input means establishing the time base of the device, output means, two sets of intermittentlyoperable rotating means each including first and second means adapted to engage with one another, the first means of each set being operatively connected with said input means and the second means of each set being operatively connected with said output means, engaging means on the first and second means of said first set operative to seek entrainment of said output means upon mutual engagement thereof, engaging means in the first and second means of said second set including blocking means for temporarily preventing rotation of said output means until a predetermined relatively short period of time after said mutual engagement of said first-mentioned engaging means, one of said set means including yielding means enabling relative movement of said input means and said output means during said period of time, and means in said engaging means to rotate said output means through only a predetermined angle after said blocking means becomes ineifective after elapse of said period of time.

9. A step by step control device, especially for driving rotating commutators, comprising driving means for establishing the time base of the device, a first disk and a second disk driven by said driving means, said disks being of essentially circular profile, driven shaft means including a first and a second toothed wheel each having the same number of teeth and mounted for common rotation therewith, one toothed wheel each being arranged facing a respective disk, the teeth of one of said Wheels having a phase displacement with respect to the teeth of the other wheel substantially equal to one-half of the pitch of the wheels, said first disk being provided with notch means followed directly in the normal direction of rotation thereof by a projecting tooth means adapted to engage with the teeth of said first wheel, said second disk having projecting tooth means adapted to engage with the teeth of said second wheel and displaced ahead, in the normal direction of rotation of said disks, with respect to the corresponding tooth means of said first disk in such a manner as to insure that a tooth of said first wheel engages the notch means of said first disk means as soon as said notch means arrives opposite said first toothed wheel, and means for elastically mounting the projecting tooth means of said first disk on the latter.

10. A step by step control device, especially for driving rotating commutator-s, comprising driving means for establishing the time base of the device, a first disk and a second disk driven by said driving means, said disks being of essentially circular profile, driven shaft means including a first and a second toothed Wheel each having the same number of teeth and mounted for common rotation therewith, one toothed wheel each being arranged facing a respective disk, the teeth of one said wheels having a phase displacement with respect to the teeth of the other wheel substantially equal to one-half of the pitch of the wheels, said first disk being provided with notch means followed directly in the normal direction of rotation thereof by a corresponding projecting tooth means adapted to engage with the teeth of said first wheel, said second disk having projecting tooth means adapted to engage with the teeth of said second wheel and displaced ahead, in the normal direction of rotation of said disks, with respect to the corresponding tooth means of said first disk in such a manner as to operatively insure that a tooth of said first wheel engages the notch means of said first disk means as soon as said notch means arrives opposite said first toothed wheel, and brake means to eifectively brake said output means and thereby prevent chattering of the teeth of said first wheel after each stepby-step movement.

11. A precision step by step control device, especially for driving rotating commutators to produce sharply defined and accurately spaced signals, comprising continuously rotating input means establishing the time base of the device, output means, two sets of intermittently-operable rotating means each including first and second means adapted to engage with one another, the first means of each set being operatively connected with said input means and the second means of each set being operatively connected with said output means, engaging means on the first and second means of said first set operative to seek entrainment of said output means upon mutual engagement thereof; engaging means in the first and second means of said second set including clocking means for temporarily preventing rotation of said output means until a predetermined relatively short period of time after said mutual engagement of said first-mentioned engaging means, one of said set means including yielding means enabling relative movement of said input means and said output means during said period of time, and means in said engaging means to rotate said output means through only a predetermined angle after said blocking means becomes ineffective after elapse of said period of time including brake means for effectively braking said output means.

12. A step by step control device, especially for driving rotating cornmutators, immersed within an oil bath and comprising driving means for establishing the time base g of the device, a first disk and a second disk driven by said driving means, said disks being of essentially circular profile, driven shaft means including a first and a second toothed wheel each having the same number of teeth and mounted for common rotation therewith, one toothed wheel each being arranged facing a respective disk, the teeth of one said wheels having a phase displacement with respect to the teeth of the other wheel substantially equal to one-half of the pitch of the wheels, said first disk being provided with notch means followed directly in the normal direction of rotation of said disk means by a corresponding projecting tooth means adapted to engage with the teeth of said first wheel, said second disk having projecting tooth means adapted to engage with the teeth of said second wheel and displaced ahead, in the normal direction of rotation of said disks, with respect to the corresponding tooth means of said first disk in such a manner as to operatively insure that a tooth of said first wheel engages into the notch means of said first disk means as soon as said notch means arrives opposite said first toothed wheel.

13. A step by step control device, especially for driving rotating commutators, comprising driving means including a synchronous motor for establishing the time base of the device, a first disk and a second disk driven by said driving means over a speed-reduction gear, said disks being of essentially circular profile, driven shaft means including a first and a second toothed wheel each having the same number of teeth and mounted for common rotation therewith, one toothed wheel each being arranged facing a respective disk, the teeth of one said wheels having a phase displacement with respect to the teeth of the other wheel substantially equal to one-half of the pitch of the wheels, said first disk being provided with notch means followed directly in the normal direction of rotation thereof by a corresponding projecting tooth means adapted to engage with the teeth of said first wheel, said second disk having projecting tooth means adapted to engage with the teeth of said second wheel and displaced ahead, in the normal direction of rotation of said disks, with respect to the corresponding tooth means of said first disk in such a manner as to operatively insure that a tooth of said first Wheel engages into the notch means of said first disk means as soon as said notch means arrives opposite said first toothed wheel.

14. A step by step control device, especially for driving rotating commutators, comprising driving means for estabiishing the time base of the device, a first disk and a second disk driven by said driving means over a speedreduction gear, said disks being of essentially circular profile, driven shaft means including a first and a second toothed wheel each having the same number of teeth and mounted for common rotation therewith, one toothed wheel each being arranged facing a respective disk, the teeth of one said wheels having a phase displacement with respect to the teeth of the other wheel substantially equal to one-half of the pitch of the wheels, said first disk being provided with notch means followed directly the normal direction of rotation thereof by a corresponding projecting tooth means adapted to engage with the teeth or" said first wheel, said second disk having projecting tooth means adapted to engage with the teeth of said second wheel and displaced ahead, in the normal direction of rotation of said disks, with respect to the corresponding tooth means of said first disk in such a manner that a tooth of said first Wheel engages into the notch means of said first disk means as soon as said notch means arrives opposite said first toothed wheel, rotating commutator means, and speed reduction gear means operatively connecting said driven shaft means with said commutator means.

15. A step by step control device, especially for driving rotating commutators, comprising driving means including a synchronous motor for establishing the time base of the device, a first disk and a second disk driven by said driving means over a speed-reduction gear, said disks being of essentially circular profile, driven shaft means including a first and a second toothed wheel each having the same number of teeth and mounted for common rotation therewith, one toothed wheel each being arranged facing a respective disk, the teeth of one said Wheels having a phase displacement with respect to the teeth of the other wheel substantially equal to one-half of the pitch of the wheels, said first disk being provided with notch means followed directly in the normal direction of rotation thereof by a corresponding projecting tooth means adapted to engage with the teeth of said first Wheel, said second disk having projecting tooth means adapted to engage with the teeth of said second wheel and displaced ahead, in the normal direction of rotation of said disks, with respect to the corresponding tooth means of said first disk in such a manner that a tooth of said first wheel fits into the notch means of said rst disk means as soon as said notch means arrives opposite said first toothed wheel, rotating commutator means, and. speed reduction gear means operatively connecting said driven shaft means with said commutator means, and an oil bath in which said step by step control device is immersed.

16. A step by step control device, especially for driving rotating commutators, comprising driving means includ ing a synchronous motor and speed reduction means for establishing the time base of the device, a first disk and a second disk driven by said driving means, said disks being of essentially circular profile, driven shaft means including a first and a second toothed wheel each having the same number of teeth and mounted for common rotation therewith, said toothed wheels having the same module, one toothed wheel each being arranged facing a respective disk, the teeth of one of said wheels having a phase displacement with respect to the teeth of the other wheel substantially equal to one-half of the pitch of the wheels, said first disk being provided with notch means followed directly in the normal direction of rotation thereof by a corresponding projecting tooth means adapted to engage with the teeth of said first wheel, said second disk having projecting tooth means adapted to engage with the teeth of said second wheel and displaced ahead, in the normal direction of rotation of said disks, with respect to the corresponding tooth means of said first disk by a value slightly larger than the pitch corresponding to the module of said toothed wheels and to iii the diameter of said second disk in such a manner that a tooth of said first wheel fits into the notch means of said first disk as soon as said notch means arrives opposite said first toothed wheel, and means for yieldingly mounting the tooth means of said second disk on the latter, and brake means effectively braking said output means to prevent shocks, at the end of each step-by-step movement, by the teeth of said first wheel against said first disk.

17. A step by step control device, especially for driving rotating coinmutators, comprising driving means for establishing the time base of the device, a first disk and a second disk driven by said driving means, each of said disks including the same number of projecting tooth means, driven shaft means including toothed wheels mounted for common rotation therewith, one toothed wheel each being arranged facing a respective disk, said toothed wheels having the same number of teeth, and the teeth of one whee] being out of phase with the teeth of the other by an amount corresponding essentially to a one-half pitch of the wheels, one of said disks being provided with notch means preceding immediately in the normal direction of rotation of said disk a corresponding projecting tooth means, the other disk having the tooth means arranged at a slight leading phase displacement, in the normal direction of rotation of said disks, with respect to the corresponding tooth means of said one disk, the tooth means of said other disk, during normal rotation of said disks as driven by said drive means, initially engaging a tooth of the corresponding wheel mounted on said driven shaft means and seeking to displace the same with such displacement, however, being blocked until a corresponding tooth of the wheel facing said one disk is capable of engaging in a corresponding notch means of said one disk whereupon both said toothed wheels rotate a predetermined distance.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A STEP BY STEP CONTROL DEVICE, ESPECIALLY FOR DRIVING ROTATING COMMUTATORS, COMPRISING DRIVING MEANS FOR ESTABLISHING THE TIME BASE OF THE DEVICE, FIRST DISK MEANS AND SECOND DISK MEANS DRIVEN BY SAID DRIVING MEANS, SAID FIRST AND SECOND DISK MEANS BEING OF ESSENTIALLY CIRCULAR PROFILE, DRIVEN SHAFT MEANS INCLUDING A FIRST AND A SECOND TOOTHED WHEEL EACH HAVING THE SAME NUMBER OF TEETH AND MOUNTED FOR COMMON ROTATION THEREWITH, ONE TOOTHED WHEEL EACH BEING ARRANGED FACING A RESPECTIVE DISK MEANS, THE TEETH ON ONE SAID WHEELS HAVING A PHASE DISPLACEMENT WITH RESPECT TO THE TEETH OF THE OTHER WHEEL SUBSTANTIALLY EQUAL TO ONE-HALF OF THE PITCH OF THE TEETH THEREOF, SAID FIRST DISK MEANS BEING PROVIDED WITH NOTCH MEANS PRECEDING IMMEDIATELY IN THE NORMAL DIRECTION OF ROTATION OF SAID DISK MEANS A CORRESPONDING PROJECTING TOOTH MEANS ADAPTED TO ENGAGE WITH THE TEETH OF SAID FIRST WHEEL, SAID SECOND DISK MEANS HAVING PROJECTING TOOTH MEANS ADAPTED TO ENGAGE WITH THE TEETH OF SAID SECOND WHEEL AND DISPLACED AHEAD, IN THE NORMAL DIRECTION OF ROTATION OF SAID DISK MEANS, WITH RESPECT TO THE CORRESPONDING TOOTH MEANS OF SAID FIRST DISK MEANS IN INTO THE NOTCH MEANS OF SAID FIRST DISK MEANS AS SOON AS INTO THE NOTCH MEANS OF SAID FIRST DISK MEANS AS SOON AS SAID NOTCH MEANS ARRIVES OPPOSITE SAID FIRST TOOTHED WEEL. 